A Ustream source says Shiba Inu Puppy Cam has been viewed 15 million times, for a combined 773 viewer years.

For a little perspective, note that 2008’s most popular Web video — the Jonas Brothers’ Burnin’ Up — has over four times as many views. But that only resulted in 326.3 viewer years.

In fact, as soon as Puppy Cam passes 794 viewers years, it will pass Avril Lavigne’s “Girlfriend” as the most watched Web video ever. That should happen sometime Friday.

Also, we’re willing to bet that Puppy Cam costs were far less than 25% of the production costs involved in prettying up the Jonas Brothers.

As the puppies grow up and their owners sell them, the puppy cam population continues to dwindle. But not Ustream’s traffic, says cofounder Brad Hunstable.

“All around, we’ve seen tremendous growth,” Ustream cofounder Brad Hunstable told the New York Times. “We’ve seen a spike of about 25 per cent growth in new shows, a massive spike in our unique visitors, and gotten e-mails from interested investors.”